1. Field of the Invention
The present invention relates to improved design and construction of a multipurpose medical instrument for serial collection, storage and processing of biopsy specimens.
2. The Prior Art
Capture, serial collection and storage for processing in a cassette portion of a biopsy apparatus is a complex process requiring precision of many related operations. In addition, these operations are reduced to a small scale in biopsy devices that must traverse access sites or endoscopes with operating channels ranging from 3 to 0.5 mm. Multiple specimens must be retrieved in sequence without mixing them to ensure that the site of biopsy is known and to minimize the number of instrument passes through the access passage or endoscope to the biopsy site.
The storage and processing of multiple specimens within a biopsy instrument yields a great savings of time and effort in processing the biopsies, as well as preventing specimen loss or damage during handling. This goal is facilitated by applying redundant methods for forcing the minute biopsy specimens into a storage cassette of the biopsy instrument and by minimizing the operating parts of the biopsy instrument to maximize the storage volume.
The prior art described in the spring based multipurpose medical instrument in U.S. Pat. No. 5,782,747, the disclosure of which is herein incorporated by reference, obviates the use of cumbersome metal shafts and coverings that occupy the space needed for specimen storage. Standard jaw fulcrum biopsy devices require a stiff shaft to prevent kinking and binding within the endoscope when the actuator cable(s) is pulled to close the biopsy jaws and then held to maintain jaw closure when removing the device and biopsy from the endoscope or access passage. The combined stiffness of the shaft and pull on the actuator cable(s) straightens the biopsy device and endoscope. This action moves the endoscope and biopsy device away from the biopsy site and limits maneuverability. This stiffness and uncontrolled motion also risks trauma to the biopsy site and limits access in curved lumens. A further limitation of stiff shafts is that they reduce the options for carrier instrument flexibility and maneuverability. The present invention solves these problems in a unique and unobvious way.